GM recalls 300 Cruise robo-taxis after hitting San Francisco bus

General Motors (GM) has recalled 300 Cruise robo-taxis to upgrade their autonomous self-driving software after one of the driverless units crashes into the back of a bus in San Francisco.

Luckily no one was hurt in the March 23 collision, which happened on Haight Street in San Francisco's famous Haight-Ashbury district.

The Cruise AV (autonomous vehicle) struck the rear bumper of the bus as it stopped ahead of it and sustained moderate damage. Cruise is a mostly autonomous subsidiary of GM that tests and develops self-driving cars.

According to a voluntary safety report filed with the National Highway Traffic Safety Administration (NHTSA), the Cruise robotaxi “inaccurately predicted the movement of an articulated San Francisco Municipal Transit Authority (MUNI) bus.

An articulated MUNI bus is an elongated bus made of two solid sections that has a flexible joint in the middle that effectively renders the vehicle as a whole bendable, allowing it to make certain maneuvers.

On March 25, two days after the accident, GM performed a fresh software update to address the inaccurate predictions made by the robo-taxi. Previously, the last software update for the AV was in January. Cruise says the recent update has fixed the issue.

Cruise founder and CEO Kyle Vogt said in a blog post after the accident, "Fender benders like this rarely happen to our AVs, but this incident was unique.”

“We do not expect our vehicles to run into the back of a city bus under any conditions, so even a single incident like this was worthy of immediate and careful study,” Vogt said.

Vogt pointed out that even though Cruise vehicles encounter MUNI buses everyday, it was the first collision of its kind.

“We quickly determined the bus’s behavior was reasonable and predictable. It pulled out into a lane of traffic from a bus stop and then came to a stop. Although our car did brake in response, it applied the brakes too late and rear-ended the bus at about 10mph [about 15kph],” Vogt said.

According to the NHTSA filings, the AV was slow to brake as it miscalculated the bus's actions when its initial view of the front of the bus became blocked by the rear. Instead of reacting to the real-time movements of the back of the bus, it continued to react to predictions for the front of the bus, which it could no longer see.

After thoroughly investigating the incident, the CEO said the company’s data and simulations showed that the incident was exceptionally rare and isolated.

Cruise said it submitted the NHTSA Safety Recall Report to add transparency to the public’s understanding of what happened.

Vogt said that since the Cruise fleet hit San Francisco in February 2022, the AVs have driven over one million miles in full driverless mode.

Last September, Cruise disclosed it recalled and updated software in 80 self-driving vehicles after a June crash in the bay area left two people injured.

The NHTSA opened a formal safety probe in December of the Cruise autonomous driving systems after it was reported the units "may engage in inappropriately hard braking or become immobilized."

The safety agency had determined the software may "incorrectly predict" an oncoming vehicle's path.

Meantime, it was also reported in 2022, by the local SFist news outlet, that the Cruise AVs were involved in a total of nine hit and runs.

Earlier this year, Tesla was forced to recall over 350,000 of its vehicles after the NHTSA found vehicle self-driving software did not adhere to traffic safety laws.

The faulty driver assistance system allows the vehicle to "exceed speed limits or travel through intersections in an unlawful or unpredictable manner increases the risk of a crash," according to the NHTSA.